Terminals may be divided into mobile/portable terminals and stationary terminals according to mobility. Also, the mobile terminals may be classified into handheld types and vehicle mount types according to whether or not a user can directly carry.
Mobile terminals have become increasingly more functional. Examples of such functions include data and voice communications, capturing images and video via a camera, recording audio, playing music files via a speaker system, and displaying images and video on a display unit. Some mobile terminals include additional functionality which supports electronic game playing, while other terminals are configured as multimedia players. Specifically, in recent time, mobile terminals can receive broadcast and multicast signals to allow viewing of video or television programs
As it becomes multifunctional, a mobile terminal can be allowed to capture still images or moving images, play music or video files, play games, receive broadcast and the like, so as to be implemented as an integrated multimedia player.
Efforts are ongoing to support and increase the functionality of mobile terminals. Such efforts include software and hardware improvements, as well as changes and improvements in the structural components.
In addition to those attempts, the mobile terminals provide various services in recent years by virtue of commercialization of wireless communication systems using an LTE communication technology. In the future, it is expected that a wireless communication system using a fifth generation (5G) communication technology will be commercialized to provide various services. In this regard, when a high input signal is applied to a amplifier operating in an RF frequency band, a nonlinear output signal is generated in adjacent frequency bands, thereby deteriorating the performance of the communication system.
In particular, an amplifier, such as in a 5G communication system, which operates in higher frequency bands, has lower saturated input power than the related art LTE communication system. Therefore, the amplifier, such as the 5G communication system, which operates in the higher frequency bands, has a problem of the performance degradation of the communication system due to the nonlinear output signal.